研究了由卤化锌、三苯基膦、四丁基溴化铵3种组分组成的一种高效的催化体系,在温和条件下,对催化CO2与环氧烷耦合反应能够得到高的催化活性和选择性.系统考察了反应温度、CO2压力、反应时间和不同的催化剂组分对催化活性的影响.结果表明:催化体系ZnBr2/PPh3/n-Bu4 NBr/PO的摩尔比为10︰1︰2︰1783,在CO2压力为3 MPa、反应时间5 h、反应温度为130℃及无任何有机溶剂的情况下产率可达98.1%.此催化体系对其他6种环氧烷也有很好的催化效果.
An efficient catalyst system composed of ZnX2 (X=Cl, Br, I), PPh3 (triphenylphosphine) and n-Bu4NBr ( tetrabutylammonium bromide) , was developed and showed high activity and selectivity for the coupling reaction of CO2 and epoxide under mild conditions. The effects of reaction temperature, CO2 pressure, reaction time and various compositions of the catalysts were investigated.It turned out that the yield for the coupling reaction of CO2 and propylene oxide (PO) could reach 98.1%in the presence of ZnBr2/PPh3/n-Bu4NBr/PO (molar ratio of 10︰1︰2︰1783) at a low pressure of CO2(3 MPa), short time (5 h) and mild temperature (130℃) without any organic solvents.The catalyst system was applicable to other six terminal epoxides.